1. Field of the Invention
This invention relates to compositions which are particularly useful as cheese emulsifiers, processes for preparing cheese with such compositions and cheese formulations containing such compositions. More particularly, this invention relates to sodium aluminum phosphate compositions that provide optimum available alkalinity.
Many phosphate materials are known as cheese emulsifiers for process cheese, such as disodium orthophosphate, trisodium orthophosphate, sodium hexametaphosphate, and the like. However, these materials all have serious limitations as cheese emulsifiers and therefore are not used to the extent desired for cheese emulsification. For example, disodium orthophosphate is generally satisfactory as a cheese emulsifier below about 2.1% (based on the total weight of the cheese) but when used in greater amounts, crystals of disodium orthophosphate usually from which is, of course, highly objectionable.
More recently, sodium aluminum phosphate compositions have been suggested as cheese emulsifiers. These sodium aluminum phosphate compositions have been combined with other phosphates such as disodium orthophosphate to form useful compositions for emulsifying cheese when used in levels up to about 3%. Illustrative of such compositions are U.S. Pat. Nos. 3,097,949, 3,244,535, 3,337,347, 3,554,921 and more recently U.S. Pat. Nos. 3,726,960 and 3,729,546.
2. Description of the Prior Art
Unfortunately, these known sodium aluminum phosphate compositions do not provide the optimum level of available alkalinity that a cheese manufacturer might desire in his cheese manufacturing operations. Furthermore, it has been found to be extremely difficult to obtain sodium aluminum phosphates that have reproducible available alkalinities in the heretobefore known ratios of materials used to form these known sodium aluminum phosphate compositions.
The term "available alkalinity" as used herein means the alkalinity available from sodium aluminum phosphate compositions as determined by test procedures that simulate actual cheese emulsification conditions.
In actual cheese emulsification about 3% of the emulsifier is added to the cheese (giving about 7% by weight emulsifier concentration in the water phase) at 72.+-.2.degree. C. at an average pH of about 5.8. The cheese is mixed for about 5 minutes at this temperature. Loaf cheese is then removed and slowly cooled while undergoing further processing.
The test procedures utilized to determine "available alkalinity" herein are as follows: In as rapid a sequence as possible, 4.9 grams of sample material and about 20 ml. of water (at 80.degree.-90.degree. C.) are placed in a 150 ml. tared beaker which is equipped with a magnetic stirring bar. While maintaining the temperature at 70.+-.4.degree. C., about 35 ml. of 0.5 N HCl is added. The pH is maintained at 5.8 for 30 minutes by adding 0.5 N HCl as necessary. The time, slurry temperature, pH and ml. of HCl added are recorded. The concentration should be adjusted by adding water so that the final weight of the resulting mass is 70.0 grams and has a pH of 5.8 at 70.+-.4.degree. C. This provides a concentration of 7% by weight of the emulsifier at the final conditions. The "available alkalinity" (expressed as %) can be obtained from the following equation: ##EQU1##
As discussed hereinafter it has been found that the optimum available alkalinity for many cheese manufacturing procedures is at about 15%.
It has now been found, in accordance with the present invention, that an entirely new and distinct class of sodium aluminum phosphate compositions having this desirable optimum available alkalinity, a property heretofore unrecognized, can be prepared. Furthermore, a highly unexpected and surprising characteristic of many of the sodium aluminum phosphate compositions of this invention is that they can be readily reproduced so that subsequently manufactured compositions vary only slightly from previous compositions in their available alkalinity. The new sodium aluminum phosphate compositions have, for use as cheese emulsifiers, the recognized advantages as previously described and, in addition provide both optimum available alkalinity and in most cases the reproducibility necessary to maintain consistent available alkalinities in subsequently manfactured compositions resulting in imparting useful and beneficial properties to cheese, all of which will be more fully discussed hereinafter.